A grizzly mother in Yellowstone Park was catching trout for her cubs one June day of 1891, when a friend and I came along. We went near to watch them. Mother grizzly charged; we fled. After one leap she stood still and appeared to be almost grinning at us. We went back, she charged, and again we ran, although she stopped at the end of the first leap. But the third time she leaped at us we stood our ground. She growled but came no nearer. Although her threats did not appear to be in earnest, we did not risk going closer; nor would I have risked standing even at that distance if we had been outside of the Park boundary.
One day I saw a bear who appeared to be suffering from a headache. A short time before he had eaten an enormous quantity of garbage. This may have been his first dinner at a garbage-pile. Standing up, he felt of his head with first one fore paw and then the other. Then, lying down, he endeavored to hold his head in both fore paws. He had just thrust it into a stream and was trying to rub it with his paw when I last saw him. On another occasion I noticed a bear suffering from a toothache. He felt of his tooth, clawed at it, and in a number of other ways showed his annoyance.
In the Yellowstone the environment of grizzlies was radically changed when it became a wild-life reservation. The numerous bear-population quickly discovered that in the Park it would not be shot at. Grizzlies at once wandered about near people with no attempt to conceal themselves and with the best of manners; there was no annoying of people, no crossness, no ferocity. This ideal association of people and grizzly bears went on unmarred for years.
Numbers of bears from far outside Park boundaries came to spend two or three months of each summer there, returning to home territory during the autumn. Other grizzlies left their homes outside the Park and moved in to stay. Whether the summer migrant bears or the recent residents came to the Park because of the food, the safety, or both is difficult to say. Unusual opportunities were furnished Park visitors to study and observe the grizzly, with beneficial influence on themselves. But their worrying of the bears in time proved harmful.
The bears were thoughtlessly betrayed. Increasing numbers of visitors produced large garbage-piles. People came to the garbage-piles to watch the bears feed and often teased them. The bears became cross. Sometimes there were fights among the assembled bears over the smelly feasts. The charity of the garbage-pile led them into bad habits, upset their digestions, and ruined their dispositions. But their appetite for garbage increased until they became food pensioners and garbage drunkards. Like some humans they enjoy being pensioners and insist on being supplied. If there wasn't enough garbage they raided camps and hotels. If their raid was interrupted they resented it. In due time a few of the most dyspeptic bears became bold and defiant raiders.